Transect Establishment and Survey Protocol Acoustic Bat Survey Driving Transects

Transcription

1 Transect Establishment and Survey Protocol Acoustic Bat Survey Driving Transects The following information was adapted from Using Acoustic Surveys to Monitor Population Trends in Bats, by Eric R. Britzke and Carl Herzog and R9 Acoustic Centers of Excellence by Brian Heeringa. Recording echolocation calls of bats as the researcher moves along a transect (walking, driving, canoeing, etc.) is now commonly used to monitor bat populations across the country and around the world. Ultrasonic detectors are a cost effective method for monitoring multiple bat species at large spatial scales. To run a transect using a vehicle, the microphone is typically removed from the detector and mounted on the roof via an extension cable, where it is less susceptible to road noise. (Note: When using an AnaBat detector, the green Hi microphone is required for this type of setup.) Criteria the WI Bat Program used in establishing a driving transect: 1. Be approximately 30 miles long. 2. Minimize sampling the same stretches of road (one-way straight line movement). 3. Be safe to drive at speeds not exceeding 20 mph. 4. Pass through common habitat types of the area. 5. Minimize the amount of time on roads with small forested corridors that, 10 feet above the vehicle, have complete canopy cover over them. The ultimate goal is to try and give as big an area of sampling for the bat detector as possible. 6. Be easily sampled in successive years.

2 Sampling Any type of bat detector that allows for recording of echolocation calls can be used (except time expansion systems). The important thing is that the same type of detector is used whenever transects are sampled, and transects are started at the same location each time. Surveys are run between June 1 and July 15 when bats are on their maternity range. Routes should be surveyed at least twice during the maternity period. There are 3 primary survey periods, though additional surveys may be conducted. Run 1: June 1 through June 15 Run 2: June 16 through June 30 Run 3: July 1through July15 1. A minimum of one survey is completed for each route during each of the established periods. There should be a minimum of 5 days between replicates of the same transect. 2. Weather conditions are generally pretty flexible. Monitoring should be conducted on nights that are suitable for bat activity. a. Low wind (<30 mph) b. No rain or fog (the microphone is easily damaged by moisture). c. Suitable daytime temperatures (50ºF or warmer) 3. Sampling will begin 30 minutes after sunset. 4. Drive each survey route at ~20 MPH. 5. Travel each route in the same direction every time. 6. Securely position the microphone assembly on top of the vehicle so as to be out of the wind stream as much as possible (i.e., towards the back of the cab of a pick-up, or in the middle of the roof of a sedan or SUV). Make sure the microphone is pointed straight up or slightly to the rear for the survey. 7. Fill out a datasheet for each survey night. 8. Rub your fingers in front of the microphone before starting and ending each transect.

3 ACOUSTIC BAT DRIVING TRANSECT DATASHEET Investigator Name(s): Date: Transect Name (ex. SLMC 1 ): Sunset: Odometer Start: Odometer End: Start Time Temp (F) Relative Humidity (%) Wind Speed (m/s) End Time Temp (F) Relative Humidity (%) Wind Speed (m/s) Comments (ex. Mileage, high insect noise, traffic, break in sampling, change in sensitivity level, etc.): Please send any map corrections/additions/comments to John.White@Wisconsin.gov

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8 Instructions for using External GPS and Power-pack on a Bat survey (when PDA is not being used) Beginning a bat survey: Step 1: Remove 2 silver bolts that hold plastic bracket on from the back of the detector. Insert the Compact Flash data card into the back of the detector and replace the plastic bracket with bolts. Step 2: Secure the GPS connection to the side of the detector (use two black knobbed bolts to secure cord to serial port of detector). The USB end will insert into power pack and GPS circular disc can be placed on back of the detector, secured by an internal magnet. Ensure the GPS has 2 charged AA batteries and the detector has 4 charged AA batteries. Step 3: Turn the GPS: Two different GPS power packs are illustrated. Option 1) Turn on by switching the black button to USB. NOTE: Do not move button to the lightbulb symbol, this lights-up a white LED light and DOES NOT record GPS information. Option 2) Press silver button to turn-on power pack, blue light indicates the power is on. GPS should be plugged in via USB. Step 4: Let the GPS collect signal for 30 seconds to 1 minute to ensure satellites are found and a GPS fix can be established. A red light will flash Power Pack: Option 1 Power Pack: Option 2 Power button

9 on the GPS disc if the GPS is working properly. Step 5: Press Power button on detector. The detector should automatically begin recording (red LED next to RECORD will light-up). If the Record LED light is not on, press Record/Standby button once to start the recording session. The finger snap test in front of the microphone (helps to have the volume turned-up) should cause the Data light to flicker. Ending a bat survey: Step 1: To stop recording, press Record/Standby button once on the detector (which stops the recording session). Step 2: Press Power button on the detector to power-down system. Step 3: Shut-off GPS by moving the button on the power pack to OFF, which is the middle setting on the power pack. *Many additional surveys can be conducted on the same data card; there is no chance of losing or writing-over existing data that is stored on CF data card. Data card will be sent to Madison for data offloading and analysis.

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11 Disclaimer regarding microphone assembly magnets